This work was funded by the European Research Council (ERC) under the European Union’s Horizon 2020 Research and Rnnovation program (MiTopMat, Grant No. 715730). This project received funding from the Swiss National Science Foundation (Grant No. PP00P2_176789). M.G.V., I.E., and M.G.A. acknowledge the Spanish Ministerio de Ciencia e Innovacion (Grant No. PID2019-109905GBC21). M.G.V. acknowledges support from Programa Red Guipuzcoana de Ciencia Tecnología e Innovación 2021, No. 2021-CIEN-000070-01 Gipuzkoa Next, and the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) through GA 3314/1-1–FOR 5249 (QUAST). This work has been supported in part by the Basque Government (Grant No. IT979-16). This work was also supported by the European Research Council (Advanced Grant No. 742068 TOPMAT), the Deutsche Forschungsgemeinschaft (Project ID No. 258499086 SFB 1143), and the DFG through the Würzburg-Dresden Cluster of Excellence on Complexity and Topology in Quantum Matter ct.qmat (EXC 2147, Project ID No. 39085490).

The cascade of electronic phases in CsV3Sb5 raises the prospect to disentangle their mutual interactions in a clean, strongly interacting kagome lattice. When the kagome planes are stacked into a crystal, its electronic dimensionality encodes how much of the kagome physics and its topological aspects survive. The layered structure of CsV3Sb5 reflects in Brillouin-zone-sized quasi-two-dimensional Fermi surfaces and significant transport anisotropy. Yet here we demonstrate that CsV3Sb5 is a three-dimensional (3D) metal within the charge density wave (CDW) state. Small 3D pockets play a crucial role in its low-temperature magneto- and quantum transport. Their emergence at TCDW≈93K results in an anomalous sudden increase of the in-plane magnetoresistance by four orders of magnitude. The presence of these 3D pockets is further confirmed by quantum oscillations under in-plane magnetic fields, demonstrating their closed nature. These results emphasize the impact of interlayer coupling on the kagome physics in 3D materials.

Peer reviewed